in both, whereas myristic, palmitoleic, and oleicacids predominated in the triglycerides and doco-sahexaenoic acid in the complex lipids. Thus, thecomplex lipids were much more unsaturated thanthe triglycerides. In view of this observation andthe fact that the complex lipids of antarctic fishdo not show a higher degree of unsaturation thanthe complex lipids of fish living at higher environ-mental temperatures, the following conclusions werereached: The relatively high degree of unsaturationof the total lipids of fish living at low environ-mental temperatures (observed previously by manyother investigators) is due to a relatively high pro-portion of complex lipids with respect to triglyc-erides.

The determination by pancreatic lipase hydrolysisof the fatty-acid distribution in the triglycerides oftwo fish, Electrona antarctica and Argyropelecushemigvmnus, showed that stearic acid occupiesmainly the 1,3-positions in both triglycerides, anddocosahexaenoic acid predominates the 2-position.The distribution of all of the other acids differedfrom one fish to another. The fatty-acid arrange-ment in the triglycerides of Electrona antarcticaresembled that in the Euphausia triglycerides.

Reference

Jeffrey, Lela M., N. R. Bottino, and R. Reiser. The dis-tribution of fatty acid classes in lipids of antarctic eu-phausids. Antarctic Journal of the United States, 1(5):209.

Research on Antarctic Isopods,1966-1967

ROBERT J. MENZIES *and ROBERT Y. GEORGE *

Duke University Marine Laboratory

Besides discovering several new and known spe-cies of antarctic deep-sea isopods in the Eltanincollections during the past year, Duke University bi-ologists have made special efforts to achieve an im-portant objective of this continuing project, i.e., de-termine the origin and the zoogeographic character-istics of abyssal antarctic isopods. A typical deep-seagenus, Storthyngura, comprising 38 species (includ-ing 12 antarctic species), was chosen for a thoroughanalysis of species characteristics and affinities to

* Now at Department of Oceanography, Florida StateUniversity.

species elsewhere. Close attention to species differ-entiation was necessitated by the little-known factthat zoogeographic separation at abyssal depth oc-curs mainly at the species level (George and Men-zies, 1967a and 1967b). For considerations of phy-logenetic relationships, it is essential that "true"affinity between species be established by moresophisticated and less subjective methods. Thisnecessitated a detailed qualitative analysis and aquantitative computer analysis of 158 characteris-tics by employing the programming of Rogers andFleming (IBM 7044 and CEC 1604) of the taxo-metric computer program at Colorado State Uni-versity, Ft. Collins, Colorado. The results indicatea high-percentage relationship between the com-puter and qualitative analyses. On the basis of thisdetailed study, a phylogenetic tree showing the dif-ferent evolutionary routes has been constructed.Further, the geographical distribution of morpho-logically allied species indicates that 100 percent ofthe groups represented in the Antarctic have certainstriking patterns. This group analysis suggests thatthe genus probably evolved in the antarctic andradiated into other world oceans.

Data on Storthyngura species collected by El-tanin in different months of the year in the ScotiaSea indicate a seasonal or cyclic reproductive ac-tivity in abyssal organisms (George and Menzies,1967c). Since there are no known seasonal envi-ronmental changes in the deep sea comparable inmagnitude to those at the sea surface, the persistentbreeding cycle of deep-sea isopods may reflect theirderivation from shallow-water organisms.

Based on the isopod material collected on AntonBruun's Cruise 11 and Eltanin's Cruise 3, a mono-graph entitled The systematics, distribution, andorigin of marine isopod Crustacea of the Mime-Edwards Trench has been compiled. The ecologi-cal and distributional data gathered over 500-rnincrements to a depth of 6,200 m have been sub-jected to a factor analysis in order to determinethe salient features correlated with abyssal life.The results led us to question the concept that ahadal or ultra-abyssal fauna is an ecologic or fau-fistic unit with distinctive characteristics (Menziesand George, 1967).

A study was made of the distribution of eye-bearing and blind benthic isopods in relation todepth and latitude. The ocular index, i.e., 50 per-cent of species blind, is located at a shallow depth(100-500 m) at arctic and antarctic latitudes andin deeper water (1,300 m) at lower latitudes. Thisequatorial submergence of ocular index 50 canprobably be explained by the emergence of typicallyabyssal genera to shallow water in polar regions.

September-October, 1967 195

(Photo hr author)

A sinail portion of an aggregation of Alasko-zetes antarcticus (Michael).

Nonetheless, on the basis of the presence or ab-sence of eyes alone, it is a reasonable conclusionthat the shallow waters of the polar regions areequivalent to much greater depths in the tropics(Menzies et a!, submitted).

References

George, R. Y. and R. J. Menzies. 1967a. Species of Stor-thyngura (Crustacea, Isopoda) from the Antarctic withdescriptions of six new species. Crustaceana. In press.

George, R. Y. and R. I. Menzies. 1967b. Distribution andprobable origin of the species of the deep-sea genus Stor-th yngura. Crustaceana. In press.

George, R. Y. and R. J. Menzies. 1967c. Indication of cyclicreproductive activity in abyssal organisms. Nature, 215(5103): 878.

Menzies, R. J. and R. Y. George. 1967. Reevaluation ofthe concept of hadal or ultra-abyssal fauna. Deep SeaResearch. In press.

Menzies, R. J., R. Y. George, and G. T. Rowe. A visionindex for isopod crustaceans related to latitude and depth.Submitted to Nature.

Studies of the MiteAlaskozetes antarcticus (Michael)

VERNE PECKHAM

Department of EntomologyBernice P. Bishop Museum

Alaskozetes antarcticus (Michael) is a large(1,059.0 micron) orbatid mite which is suitable forsome physiological and behavioral testing. During1966, it was studied at Norsel Point on the Antarc-tic Peninsula by representatives of the Bernice P.Bishop Museum.

This mite occurs in dense aggregations on thesides and undersurfaces of rock rubble and in smallcracks on vertical cliffs. It is associated with soilmaterials that are rich in phosphorus and potas-sium, which probably come from animals directlyor indirectly associated with the marine environ-ment. For example, conspicuous concentrations ofA laskozetes were observed near the wallows of thesouthern elephant seal, Mirounga leonia, where theammonia and organic nitrogen content of the soilwas sufficiently high to limit the growth of chloro-phytic algae.

Alaskozetes is found at the periphery of avianroosting and nesting sites, and it occurs within thefeather debris left by the giant petrel, Macronectesgiganteus, which nests at Norsel Point. OftenAlaskozetes is associated with microalgae, such asChiorococcum sp., and it may be seen on the thallusof the chlorophyte Prasiola sp.

Alaskozetes is occasionally found in aggregationsthat have an internal three-layered stratification.Eggs and larvae form a layer adjacent to the sub-stratum. They are covered by the empty skins andthe inactive bodies of larger deutonymph and tn-tonymph juveniles. The uppermost layer iscomposed of the resting bodies of newly emergedadults, individuals that have lived through the win-ter, and gravid females.

In the larger aggregations, accumulations ofmoulted skins that approach 0.5 cm in thicknessform a diversified and protective habitat for smalllarvae.

Fecal pellets from the adult Alaskozetes transmitviable chiorococcoid algae into areas where eggincubation occurs. This fact was demonstrated bythe preparation, in the laboratory, of algal culturesfrom isolated fecal pellets. Also, newly emergedlarvae were observed feeding on the algae Eremo-

ii(Photo by author)

Alaskozetes antarcticus (Mi-chael). The adult mite is

about 1 mm in length.

196 ANTARCTIC JOURNAL